On the Level by Greg Silsby

As I visit churches, I sometimes see a small adhesive strip or dot next to each slide fader, indicating its "correct" operating position. Similarly, sound operators will sometimes move faders to various positions and tell me, "We operate our pulpit mic here, our choir mics here and a hand-held wireless here." The fader levels they show me often vary considerably.

Believing that there is one right position for each fader makes some operators afraid to ever move a fader. And when they do, it is often noticeably late. The signal level coming into each channel determines the setting for the "gain" (or "trim") control, located at the top of the channel strip. (See Christian Sound & Song, Issue No. 1.) With each gain control set properly, the faders should all sit at the "unity-gain" position to produce a mix of equal levels. At least this would be true if the level of each signal were to remain constant.

But levels don’t stay constant. If a singer sings much louder or closer to the mic than she did when the gain was set during the sound check, the gain should be reduced to lower the chance of distortion and allow the fader to move within its optimal range. A lapel mic output can vary dramatically, depending upon its placement. A pulpit mic may be used by several different people during one service, each speaking at a different level and at a different distance from the mic. The fader, and possibly even the gain, should be adjusted to compensate for these differences.

When you change a channel’s E.Q., you increase or decrease the level of certain frequencies before the signal gets to the fader. This means the gain setting may also need readjustment. As more sources are added to a mix, the level of each channel will need to be lowered slightly if you want to maintain a constant overall sound level. The same is true of adding effects. Adding reverb to a channel equals more of that channel. To keep the level the same, lower the fader setting accordingly.

Fader levels often need to be raised to improve a system’s signal-to-ambient-noise ratio. In this case "noise" simply means any sounds (good or bad) that interfere with the congregation’s ability to hear and understand what is being presented. This may mean bringing a soloist’s voice out over a choir or instruments, or a pastor’s voice over a noisy air-handling system.

Greg Silsby

Commercial Sound & Broadcast Guy, Mackie Designs, Inc.

Gregs@mackie.com 800-898-3211